Preheat the oven to 350 degrees Fahrenheit. Lightly spray an 8 x 8 x 2-inch baking dish with non-stick cooking spray. Line the pan with enough parchment paper to overhang the sides. This makes the removal of the bars easy!
Brownie Layer
Add 5 tablespoons cubed unsalted butter to a medium saucepan and cook over medium heat until light brown caramel in color, about 5-10 minutes. Make sure to keep and eye on it so butter does not burn. It also helps to use a light colored saucepan for this.
Pour the browned butter into a large bowl along with ⅓ cup granulated sugar, ⅓ cup light brown sugar, ⅓ cup plus 1 tablespoon unsweetened cocoa powder, ¼ teaspoon salt, ½ tablespoon instant coffee granules, and ¼ teaspoon baking powder. Stir until combined and allow to rest for 5 minutes or until the mixture has cooled down.
Stir in 1 large egg and 1 teaspoon vanilla extract and mix until batter has a nice sheen to it.
Fold in ⅓ cup all-purpose flour and ¼ cup chocolate chunks or chocolate chips and stir until combined.
Pour the brownie batter into prepared baking dish and set aside.
Chocolate Chip Cookie Layer
In a stand mixer with the paddle attachment cream 5 tablespoons softened unsalted butter, 5 tablespoons softened unsalted butter4 tablespoons light brown sugar, and 2 tablespoons granulated sugar.
Add in 1 large egg and 1 teaspoon vanilla extract and mix until combined.
In a medium bowl mix together 1 teaspoon cornstarch, ¼ teaspoon baking soda, ⅛ teaspoon baking powder, ¼ teaspoon salt, and 1 ¼ cup all-purpose flour.
Add the flour mixture to the butter mixture on low just until combined. Do not overmix.
Fold ½ cup semi sweet chocolate chips into the cookie dough.
Drop large spoonfuls of cookie dough and spread carefully. Bake for 25-30 minutes. Cool the bars completely before slicing.